Gamerz Heaven!

Kaito Suzuki discovers a video game, Gamerz Heaven, that transports him to another different dimension. Upon arriving in the bizarre new world, Kaito discovers a cute little boy known as the "navigator," which he names Nata. Everyone in Gamerz Heaven is out to capture Nata, and Kaito can only beat the game by saving him. This will be difficult for Kaito, as Gamerz Heaven is only a beta version with a limited number of saves. Kaito soon discovers in that everything that happens in Gamerz Heaven affects the real world, and characters that die in the game are wiped from the memories of everyone in his dimension.

(Source: ANN)

Gamerz Heaven! had two volumes published in English as Gamerz Heaven by ADV Manga from December 7, 2004 to February 22, 2005 before the license was dropped and the publisher went defunct.